The Obama administration on Monday offered a comprehensive legal defense of its signature climate-change regulation limiting carbon emissions from power plants, telling an appeals court that the rule is well within the bounds of its authority. The Environmental Protection Agency, writing in a 175-page brief submitted to the U.S. Court of Appeals for the District of Columbia Circuit, said the regulation was critical to addressing what it said was the most important environmental challenge facing the U.S. The Clean Air Act provides the agency “well-established authority to abate threats to public health and welfare by limiting the amount of air pollution that power plants pump into the atmosphere,” the EPA said. The agency said its opponents “seek to thwart any federal limitation” of power plant emissions of heat trapping gases, “or at least limit […]